In the case where a molded article composed of a resin having a relatively low melting point or softening point, such as a polyolefin, is bonded to another member, an adhesive, which needs to be heated at the time of bonding, such as a hot melt type adhesive, has not been used ordinarily. This is because there is a possibility that due to heating temperature at the time of bonding the molded article composed of a polyolefin resin or the like is softened to be deformed. Furthermore, in the case where a member to be bonded is heavy, there is also a possibility that the hot melt type adhesive cannot be sufficiently solidified because of insufficient cooling after heat bonding and consequently, the member is peeled off due to failing to withstand the weight of the member.
Therefore, such a molded article has been bonded by using a solution type or reaction type adhesive, or bonding or pressure-sensitive adhesion thereof has been performed by daringly adopting a means such as welding or a pressure-sensitive adhesive.
Also, it has been known: a film adhesive for heating to be bonded only using a polyolefin, as described in Patent Document 1; forming a layer composed of an acid-modified polyolefin resin as a primer layer and forming thereon an adhesive layer composed of an olefin elastomer resin, as described in Patent Document 2; and a layer containing an ethylene polymer, an α-olefin crystalline polymer, a block copolymer, and maleic acid-grafted polypropylene, functioning as an adhesive layer between a polyolefin layer and a barrier layer, as described in Patent Document 3.